s1 = {"刘能","张三","皮长山"}
s2 = {"张三","李四"}
print(s1 & s2)
print(s1.intersection(s2))
print(s1 | s2)
print(s1.union(s2))
#差集
print(s1 - s2)
print(s1.difference(s2))

s3 = [1,1,2,2,3,4,5,5,6,6,7,8,9]
print(s3)
a = set(s3)
print(type(a))
print(list(a))